Definetly a Warmer Weekend setting up as High Pressure Builds over Western Canada. In time, a cut off low develops over Northern California adding to unstable air and presenting the chance of some showers, mainly later next week. The Dweebs do not expect any snowfall on Mammoth Mtn as freezing level 13K….El Nino continues to develop with prospects for at least a moderate event with lower chances of a major event..

3 weeks
by in Mammoth Weather Outlook

Strong upper ridging is building north over CA and temps will rise to the low 60s in Mammoth this weekend, then mid to upper 60s later next week. Run off conditions once again will be brisk into next week.  Strong positive phase PNA pattern is developing as well; very El Nino like. Enjoy the warmer weather this weekend into next week, however, lots of build ups expected next week with the slight chance of showers.  Major snowcover over the upper elevations still keeping convection to a minium over our local mts.

As mentioned earlier, another cool spell is possible during the first half of June.

 

Here are comments from the CPC regarding ENSO:

Synopsis:  A transition from ENSO-neutral is expected in the next couple of months, with a greater than 90% chance of El Niño persisting into the Northern Hemisphere winter.

During April, above-average sea surface temperatures (SSTs) expanded slightly westward to the east-central equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño-3.4 index value was +0.4°C, with the easternmost Niño-3 and Niño1+2 regions at +0.8°C and +2.7°C, respectively [Fig. 2]. Area-averaged subsurface temperatures anomalies continued to increase [Fig. 3], reflecting widespread positive temperature anomalies below the surface of the equatorial Pacific Ocean [Fig. 4]. Low-level wind anomalies were westerly during mid-April before switching back to easterly by the end of the month. Upper-level wind anomalies were westerly across most of the Pacific Ocean. Suppressed convection was observed over parts of Indonesia and anomalies weakened near the Date Line [Fig. 5]. While the warming near coastal South America remains striking, the basin-wide coupled ocean-atmosphere system remained consistent with ENSO-neutral.

The most recent IRI plume also indicates El Niño is likely to form during the May-July season and persist into the winter [Fig. 6]. The combination of a forecasted third westerly wind event in mid-late May, and high levels of above-average oceanic heat content, means that a potentially significant El Niño is on the horizon. While at least a weak El Niño is likely, the range of possibilities at the end of the year (November-January) include a 80% chance of at least a moderate El Niño (Niño-3.4 ≥ 1.0°C) to a ~55% chance of a strong El Niño (Niño-3.4 ≥ 1.5°C). It is still possible the tropical atmosphere does not couple with the ocean, and El Niño fails to materialize (5-10% chance). In summary, a transition from ENSO-neutral is expected in the next couple of months, with a greater than 90% chance of El Niño persisting into the Northern Hemisphere winter [Fig. 7].

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Additional perspectives and analysis are also available in an ENSO blog. A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 8 June 2023.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: [email protected].

Screaming message is, no matter what you read or hear, no matter how strong an El Niño events gets, it has to be a full basin El Nino which gives it the highest odds of it coupling with the westerlies and bringing a big wet winter to CA.

Another thought is, do we really want another big wet winter in CA?

El Niño winters usually are associated with positive phase PNA pattern.  This pattern often brings higher snow levels than last winter which favored negative phase PNA pattern.
positive PNA often times bring heavy wet snow events and higher elevation rain.

Again a lot of this will be determined by whether EL Nino couples with the westerlies. No one knows that yet.

Dr Howard and the Dweebs….

 

 

Chilly Unsettled period setting up for the Sierra next week……A real oppertunity to break 875 inch snowfall record on top of Mammoth Mt…..A Record that is little chatted about but Monumental….

1 month
by in Mammoth Weather Outlook

After near record high temperatures this week, the warm upper high is currently shifting east….500Mb Heights are falling, cooling is occuring in the coastal cities of Northern CA and breezy weather has returned.  Being that the Sun angle is now mid August like, surface convection will occur where ever possible, except over snowcover. The closed low developing off the coast will create massive upper divergence over Eastern California. QPF  indicated by the CRFC shows up to 1.40 over Yosemite during mid week. Freezing levels in the 5K to 7K range.  Precipitation will be mostly convective and TSRW will produce the best amounts.  Would love to see current 875 inch snowfall record amount over top of Mammoth Mt broken with possible 900 inches in sight. You never know as it could happen.   In the meantime, the heavy spring thaw weather will take a back seat as colder temps will slow down the melt. Highs some days mid week will cool to the low 40s with lows in the 20s. Best days and nights for precip will be Tuesday through Friday. Hope Mammoth Mt keeps tabs on the snowfall on the upper Mt to see if a 900 inch record occurs by weeks end.

Next long range seasonal weather concern will be related to El Nino. El Ninos can be tricky. Big El Ninos are not always wet in California as they need to be “Full Basin”  Will this be full basin warm El Nino?  That will be up to the experts to varify.  What’s a non full basin EL Nino” It’s called a Modoki event.

 

 

 

Milder days ahead this weekend through next week as the Sierra Thaw resumes… Next chance for unsettled weather seems to be in early May….

2 months
by in Mammoth Weather Outlook

4/23/2023

It was a beautiful weekend in the high country. High temperatures in town were in the low 50s and lows in the 30s. It was a bit breezy as expected. The thaw was in full swing with Mid August like Sun. In that the snowpack remains very deep and wide spread, surface enhanced convection was quite surpressed. It will take some strong upper divergence to create meaningfull precipatation here in the high country. This new week will begin much like this weekend. However, further height rises mid week into the weekend will provide for further warming. By mid week, highs could hit mid to upper 50s. Then low 60s possible by Thursday or Friday. 60s is really tough with the amount of snowcover we have, so time will tell.  With the increase in run off later this week, there is bound to be some issues in the mid and lower elevation areas of Mono and Inyo Counties.  Beyond next weekend, as touted, a change in the pattern is possible during the first week in May. A trough or closed low is expected to develop offshore. Upper divergence is expected to develop creating lots of unstable air. Again, with all the snowpack over the Sierra, that will to some degree, inhibit the type of storminess that benifits from surface CAPE. Nevertheless, the chance of showers, potential thunder and snowfall is still a possibility during the first week of May.

Next update the end of next week, hopefully….

 

The Dweeber…………….;-)

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The Cold Trof that brought a inch of snow to Mammoth Mt yesterday along with strong gusty winds in the high country is continuing to shift east through Rockies.  Strong height rises are occuring over the far Eastern Pacific and should shift inland this weekend. Its possible that this ridge and pattern could hold a good part of next week and even into the end of the month. However, there is a Great Basin/Rocky Mtn slider that will kick up more wind, Monday into Tuesday. Overall, nicer weather with high temperatures pushing well into the 50s at times in town will really increase the snow melt.  There will be periods of afternoon winds, some days stronger than others. Lows at night will move up in the 30s over the weekend.  At this point, the Dweebs do not likley see a major change in the pattern to unsettled, until the end of the Month or more likley early May. Inter seasonal maps show a chilly period returning with the possibility of some snowfall the first week of May, into possibly the 2nd week of May.  This longer range is of course more speculative and subject to change.

Extensive Snowmelt is expected over the next 10 days……

 

Dr Howard and the Dweebs……………….:-)